-
Notifications
You must be signed in to change notification settings - Fork 2
Extensions
This page gives an overview of common extensions needed for Medication and MedicationRequest resources. Explanation and examples of European national and crossborder requirements/implementations are provided as justification for change request. National implementations are mostly of ePrescription or Medication List, as the latter is usually more or less dependent on national ePrescription system.
https://jira.hl7.org/browse/FHIR-45874 - Medication classification (marked Resolved, but the resolution is conflicting with 46066)
https://jira.hl7.org/browse/FHIR-46066 - Information request regarding classification (marked triaged, needs followup)
https://jira.hl7.org/browse/FHIR-46408 - Combination package representation in Medication resource
https://jira.hl7.org/browse/FHIR-46413 - Medication characteristics
https://jira.hl7.org/browse/FHIR-46414 - Medication.definition - add reference options to definitional resources
https://jira.hl7.org/browse/FHIR-45876 - Medication name
https://jira.hl7.org/browse/FHIR-46416 - Medication size of item
https://jira.hl7.org/browse/FHIR-46607 - Ingredient role/type vs isActive
https://jira.hl7.org/browse/FHIR-47251 - Multiline prescription
Justification:
Data element is present in eHN guidelines for ePrescription and Patient Summary. It is already implemented in MyHealth@EU services as an independent data element in CDA. As crossborder medication does not take its concepts from a controlled vocabulary, the code of the product is typically provided as identifier and name of the product is clearly the name of the marketed product (present only for branded products). This data element is likely to be included in European EEXHR data exchange format, which will be mandatory for all EHRs.
National implementations:
- Finland: product name is provided as simple extension on MedicationKnowledge (contained in Medication) (link).
- Sweden: product name is part of a complex extension 'Article info' on Medication (link). Also, historical product names are profiled with the usage period.
- The Netherlands: product name is provided in code.text, and it is meant for products that do not have a code (link).
- Switzerland: product name is in code.text while code is not mandatory and is used for classifications as well (link).
- Estonia: product name is simple extension (link).
Technical considerations:
Name as a separate data element is needed as current implementations show it's either used as an extension or in code.text where it can not always be considered the correct use of the data element. There is no indication in the Medication resource that the product name should appear under code.text, even though it's often provided as an advice in Zulip chat.
When defining the extension, crossborder and/or multilanguage implementations could be considered, and extra elements for refining name type and name language could be defined. This would also correspond to ISO IDMP.
Justification:
Product classification is present in eHealth Network guidelines for ePrescription and it's used for WHO ATC classification of the product. It is already implemented in MyHealth@EU services as an independent data element in CDA: currently for ATC, but potentially for PhPID in the future.
In national implementation of prescription and medication lists, product classification element is needed for a variety of different classifications, ATC being the most international one. One product may have several different classifications, all needed to be present at the same time. Therefore, the extension should be repeatable (sliceable).
National implementations:
- Switzerland: ATC is expected under code.coding. (link).
- Sweden: Multiple data elements are used that could be considered different classifications - for example "productType" under one complex extension (nllArticleInfo) or "narcoticClassification" under another complex extension (nllArticleRegulations). ATC is expected under code.coding. (link)
- Finland: Multiple simple extensions for different classifications - typeOfMedicinalProduct, CNSdrug. ATC is expected under code. (link)
- New Zealand ATC is a separate extension under Medication (link).
Technical considerations:
Using ATC in .code element is common practice but not in line with FHIR guidance for product information (https://build.fhir.org/product). Other categories are provided in extensions. For additional classification a data element (or common extension) like .classification or .category is needed. This should have a cardinality of 0..* to allow slicing and using multiple categories for one product.
(possibly extension needed for dose form type or different dose forms for one product)
Data element is present in eHealth Network guidelines for ePrescription and eDispensation Extension is only needed if used as an independent characteristic. Low priority.
Package type (container type) is present in eHealth Network guidelines for ePrescription and eDispensation and it is implemented in MyHealth@EU services as an independent data element in CDA. However, it is a data element often dismissed by member states.
Justification:
eHealth Network guidelines for ePrescription include data element Pack Size which is described as a class or a requirement rather than a single element. This means that the pack size should be described in a way that packages containing liquids in smaller containers or multiple different items should be modelled accordingly.
Overall pack size (number of items) corresponds to Medication.totalAmount. When the package contains multiple different items, layered modelling is needed.
In case of liquids totalAmount is needed to show the number of items (5 vials), but the size of each item is also needed (3ml vial) - thus, an extension 'containedQuantity' is needed on item level.
totalAmount does not match the European Medicines Agency's way of expressing Pack Size. It is worth considering if totalAmount should be repeatable to allow easier transformation from regulatory/registry information to clinical/logistical.
National implementations:
- Estonia: Size of contained manufactured item is defined as a simple extension (link).
- New Zealand: Complex extension on Medication that contains number of items and size of item (link.
(reference from .item)
(modelling not clear for the profile)
Justification:
Overall quantity of prescribed product is a requirement in eHealth Network Guidelines for ePrescription and eDispensation. It is allowed to be number of packages or countable items or in mass/volume units. Depending on national legislation, this quantity may or may not be dispensed in one dispensation.
Overall amount per prescription (not per dispensation) is also implemented in MyHealth@EU crossborder ePrescription.
National implementations:
- Sweden: Complex extension containing total prescribed amount is extended from .dispenseRequest (link)
- Finland: Extensionfor overall prescribed amount is under .dispenseRequest (link)
Technical considerations: Occasionally prescribed amount is not expressed at all on request as it is meant to be calculated from the dosage. For implementations that only allow one dispensation per request, workaround can be used (number of fills = 1, overall prescribed amount = dispenable amount per dispense).